The present invention relates to a remote control toy car and, more particularly, to a remote control toy car control system, which has a dual-gearshift position transmission mechanism, a forward backward transmission control mechanism, and a differential assembly arranged into a system.
Regular gasoline engine remote control toy cars commonly use a transmission mechanism to increase the torque. However, because the transmission mechanism of a conventional gasoline engine remote control toy car provides only one transmission mode, it is less efficient to accelerate the speed, and the torsion cannot be increased during low speed. In order to eliminate these problems, dual-gearshift position transmission mechanisms are developed. However, prior art dual-gearshift position transmission mechanisms are commonly heavy, complicated, and expensive. Furthermore, the parts of the prior art high-precision dual-gearshift position transmission mechanisms wear quickly with use.
Further, regular gasoline engine remote control toy cars can be controlled to move forwards as well as backwards. However, the forward transmission and the backward transmission are controlled by two separated systems, i.e., when moving the toy car forwards, the user must start the forward transmission system to drive the toy car forwards; when moving the toy car backwards, the user must stop the forward transmission system and then start the backward transmission system. This forward backward transmission design is complicated, consumes much gasoline, and requires much installation space.
Like real cars, the wheels at the inner side and the wheels at the outer side have different speed of revolution when going round corners. In order to balance the speed between the wheels at the inner side and the wheels at the outer side when going round corners, a speed differential assembly shall be installed. However, because the forward transmission mechanism, the backward transmission mechanism, and the differential assembly are separated mechanisms, they cannot be installed in a common housing. Therefore, prior art gasoline remote control toy cars are commonly heavy and expensive.
The present invention has been accomplished to provide a remote control toy car control system, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a remote control toy car control system, which has a dual-gearshift position transmission mechanism, a forward backward transmission control mechanism, and a differential assembly arranged into a system. It is another object of the present invention to provide a remote control toy car control system, which achieves the advantages of high/low dual-gearshift position automatic shifting control, easy forward/backward steering control, impact structure, high economic effect, high performance, and stable functioning. To achieve these and other objects of the present invention, the remote control toy car control system comprises a dual-gearshift position transmission mechanism, a forward backward transmission control mechanism, and a differential assembly. The dual-gearshift position transmission mechanism comprises a first drive gear and a second drive gear fixedly mounted on the output shaft of the engine of the remote control toy car; a first driven gear meshed with the first drive gear; a second driven gear meshed with the second drive gear, the gear ratio between the first second drive gear and the second driven gear being smaller than the gear ratio between the first drive gear and the first driven gear; a transmission tube connected in series to the first driven gear and the second driven gear; a one-way axle bearing mounted between the transmission tube and the first driven gear; and a clutch fixedly mounted on the transmission tube and coupled to the second driven gear. The forward backward transmission control mechanism comprises a first gear fixedly mounted on the transmission tube of the dual-gearshift position transmission mechanism, the first gear comprising external teeth arranged around the outer diameter thereof and internal teeth arranged around the inner diameter thereof; a second gear, the second gear comprising internal teeth arranged around the inner diameter thereof and external teeth arranged around the outer diameter thereof; a movable gear adapted to be moved between a first position where the movable gear is meshed with the internal teeth of the first gear, and a second position where the movable gear is meshed with the internal teeth of the second gear; a first idle gear wheel meshed with the external teeth of the first gear; and a second idle gear wheel meshed with the first idle gear wheel and the external teeth of the second gear. The differential assembly comprises a shell; a hollow polygonal shaft mounted in the shell and inserted through the movable gear of the forward backward transmission control mechanism for enabling the movable gear to be moved axially along the polygonal shaft; a first center axle axially inserted through the hollow polygonal shaft and the transmission tube for free rotation relative to the hollow polygonal shaft and the transmission tube; a first center axle gear fixedly mounted on the first center axle; a second center axle axially coupled to the first center axle for enabling the second center axle and the first center axle to be separately rotated; a second center axle gear fixedly mounted on the second center axle; a plurality of first planet gears mounted in the shell and respectively meshed with the second center axle gear; and a plurality of second planet gears mounted in the shell and respectively meshed with the first center axle gear.